Interviewing

A couple of years ago, during a time of crisis in my company, I realized I’d
created a mess. But the scariest thing was I didn’t know what I’d done wrong.
Of all the many things I did, what, exactly, was making things go so badly? It
turned out that most of my problems were caused by bad interviewing technique. I
was setting every interview up for failure, and I didn’t know it.

Fortunately for my company, around this same time I hired a CEO coach who helped
me to put things in order and taught me what I was doing wrong. One of the first
things he did was observe me while I recruited. Afterwards he talked with me
about it. “This is your main problem,” he said. “You’re making classic
interviewing mistakes. And as a result, you can’t evaluate people well, you’ve
brought on some people who are not a fit for the organization, and a lot of the
stress you’re experiencing is coming directly from that.”

I couldn’t understand at first, but I decided to put aside my judgment and do
what he told me. And it worked. Here’s a synopsis.

The main thing I was doing was trying to sell candidates on the opportunity. I
was afraid they wouldn’t join, so I was trying to convince them to. This isn’t
inherently bad, but my fear of losing a candidate was blinding me.

The first big no-no in interviewing is to fear losing a candidate. You need to
understand that the vast majority of people you’ll talk to are not the right
fit. And you have to stop fearing that. Fear of losing a candidate will cause
you to bring on the wrong people, and a single poor fit can do more damage than
five good ones can fix.

Trying to convince someone to join leads to failing to really listen and learn
who they are. The interview is the main opportunity to truly get to know the
candidate. There’s no way you can do that when you’re afraid they won’t join.
You’re also trying to convince them they’re right for the job, and they
naturally want to believe they are, so you’re setting them up for failure too,
by preventing them from sensing and opting out of a bad situation.

The second big problem is asking hypothetical questions, such as “how would you
design this system?” or “if you were in in this situation, what would you do?”
This flies in the face of a lot of interviewing wisdom, which urges you to put
candidates into the situations they’ll actually face and see what they’d do.
There are two troubles with this approach: one, you can’t actually do it; it’s
all play-acting and not real. Two, you are telegraphing what you’re looking for,
and the candidate will parrot it back to you, perhaps unconsciously.

When you signal what you’re looking for, and ask the candidate if they can do
it, of course they’ll say they can. They can’t help it. You ask, “this job
requires a lot of persistence in the face of adversity. Can you do that?” The
candidate replies, “oh, sure! I’m the most persistent person you’ll ever meet!”
Once you’ve done this, you don’t have a chance to un-bias the process anymore.
You’ve spoiled it all. You’ll have a really hard time figuring out if this
person is actually resilient or not.

So what should you do instead? It begins with a really clear understanding of
what you’re hiring for. This is beyond the scope of this blog post, but
understanding at a very deep level what you’re trying to achieve with this hire
is absolutely vital. Once you know that, you can listen and observe to see
whether the candidate has those abilities or not.

And from then on, the process is very simple. Ask only about past performance.
Period. No matter what the books and blog posts say. Don’t ask what they do.
Don’t ask what they can do. Don’t ask what they will do. Ask only what they
have already done. This is the only thing that’s true and verifiable. No
reference can tell you whether Joe will solve the problem the way he
hypothetically predicts he will (and sincerely wants to, even if he can’t). But
references can tell you whether Joe did what he claimed he did on that big
project he says he’s proud of. And by listening to how Joe talks about
challenges he’s faced, and how he tried to solve them, and what he expected to
happen, and what happened, and how it worked, and what he learned, and how he
worked with others, and how he tried it differently next time… you learn who
Joe is and how he really thinks.

This is the gold mine in interviewing. Ask questions like “tell me about a
time you…” and then just listen. Follow up with specific questions to probe
into the details. “How did you do that?” “What happened?” “Who did you do that
with?”

And, if you’re the person who’ll be checking references, the final zinger is to
ask, “Who was your boss at the time?” and then “when I call that person, what
will they tell me about this project?” This is the ultimate truth serum. You’re
telling people that you’re going to actually verify their stories. If they’re
lying to you, you’ll know right away.

Many interviews won’t be conducted at that level of scrutiny. For most
interviewers, it’s good to stay away from that; the main thing is to ask only
past-tense questions, and dig deeper with followups that get into more and more
specifics.

But… but… shouldn’t you hire for trajectory, and not just experience? Sure. You
can absolutely tell whether someone’s a shooting star by understanding how they
approached tough challenges in past jobs (even if those tough challenges were
trivial for someone with more experience). You can do this by asking questions
about what challenged them and how they responded to it.

A nice, easy to way to remember this is to ask the Most Significant
Accomplishment question. “What’s the thing you’re proudest of?” Follow that up
with deeper and deeper questions. It should be a natural conversation. The
candidate should be proud of that and should tell a story, and you’re
essentially complimenting them with your attention by asking them to tell you
more and more about it.

There’s a lot more to interviewing than this, but if you stay away from
whiteboarding, pseudo-code, role-play, hypothetical how-would-you, and anything
else that can be gotten through with acting skills or that provides the
candidate with subliminal hints about what you’re looking for, you’ll avoid the
most common traps.

I’ll end this post by saying that people who recruit fulltime, for a living, can
often get good results by ignoring some of this advice. But just like occasional
negotiators will end up being taken advantage of by those who do it for a
living, ordinary rank-and-file employees who are called upon to interview a
candidate will fail if they try to use pro techniques. They should be trained to
just ask questions and listen. They don’t recruit 40 hours a week. They aren’t
pros. All they need to do is start a conversation and keep being interested and
engaged. Just listening.

If you’re interested in books that can help you improve your hiring process, I’d
suggest taking a look at
Topgrading
by Brad Smart, or
Who by
Geoff Smart. I’ve read a lot of books on interviewing and hiring, and although
I don’t fully conform to their advice, their books are the closest published
materials I’ve found to the hiring process my CEO coach and I have developed.
Many other books are written by professional recruiters and overlook the fact
that their audience isn’t recruiters, and their advice doesn’t work for
non-recruiters. I would include in this category the book Hire With Your
Head.

See Also

I'm Baron Schwartz, the founder and CEO of VividCortex. I am the author of High
Performance MySQL and lots of open-source software for performance analysis, monitoring, and system administration.
I contribute to various database communities such as Oracle, PostgreSQL, Redis and MongoDB. More about me.